Oil seal means of a rotary engine

ABSTRACT

An oil seal means of a rotary engine comprising a plurality of oil seal rings disposed one over the other and mounted in a common annular oil seal groove formed at a side wall portion of a rotor and spring means adapted to resiliently urge said oil seal rings axially outwardly of the rotor, wherein said spring means includes positively distinguished base and spring portions, the latter extending separately and independently from the former each to operate independently as a spring to support one of said oil seal rings without being directly affected by the failure or falling down of the other spring portions.

United States Patent Sasaki 1 July 22, 1975 [54] OIL, SEAL MEANS OF A ROTARY ENGINE 3.768.936 10/1973 McCormick 418/142 [75] Inventor: Yoshio Sasaki, Toyota, Japan Primary Exammer-Wtlham Freeh [73] Asslgneez f Jldosha Kogyo Kabush'k' Assistant Examiner-Leonard Smith Kalsha, Japan Attorney, Agent, or FirmStewart and Kolasch, Ltd. [22] Filed: Nov. 9, 1973 [21] Appl. No.: 414,216 ABSTRACT An oil seal means of a rotary engine comprising a plu- [30] Foreign Application priority Data rality of oil seal rings disposed one over the other and mounted 1n a common annular o1l seal groove formed July 18, 1973 Japan 48-80284 at a s1de wall port1on of a rotor and sprmg means 52 US. Cl 418/142; 267/1.5 adapted reslenfly urge 1 Seal. anally outwardly of the rotor, wherem sa1d sprmg means 1n- [51] Int. Cl. F04c 27/00 eludes Ositivel distin uished base and s rin or [58] Field of Search 418/142. 144; 267/1.5 P y g P f t1ons, the latter extending separately and mdepen- [56] References Cited dently from the former each to operate 1ndependently 1 as a sprmg to support one of sa1d o1l seal rmgs wlthout UNITED STATES PATENTS being directly affected by the failure or falling down of 3,400,939 9/]968 JODCS 418/142 X the other spring portions 3.477,?32 11/1969 Warrick 3,718,412 2/1973 McCormick 418/142 6 Claims, 7 Drawing Figures PATENTEDJuLzzms wasaasz Y I SHEET OIL SEALMEANS OF A ROTARY ENGINE BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to oil seal means of rotary engines, and more particularly an .oil seal means to be mounted at a side wall portion of a rotor to keep oil and FIG. 1, wherein a center housing 1 having an inside surface of a trochoidal cross-sectional configuration and side housings 2 closing opposite sides of the center housing define a chamber therein, in which is positioned a rotor 4 which is movable about an eccentric shaft 3 in a planetary manner. As the rotor rotates in said chamber, the oil and gas tightness between each of the three apex points (actually lines) of the rotor having a substantially triangular side configuration and the center housing 1 is maintained by the apex seals 5, while the gas .tightness between the side surface of the rotor and the side housings 2 is principally maintained by side seals 6 and the oil tightness therebetween is maintained by annular oil seal means 7. Convention ally, the annular oil seal means 7 is often constituted to have the structure such as exemplarily shown in FIG. 2, wherein a plurality of oil seal rings 9 and are mounted in a common annular oil seal groove 8, one over the other, for the purpose of increasing the oil and gas tightening effectiveness of the oil seal means. In the oil seal means of the abovementioned structure, there is conventionally provided a corrugated spring 11 such as exemplarily shown in FIG. 3 along the bottom wall of the annular oil seal groove 8 so as to urge the oil seal rings 9 and 10 outwardly of the annular oil seal groove 8 in the direction of the rotor axis so that the tip end portions of the oil seal rings are pressed against the wall surface of the side housing to maintain oil and gas tightness therebetween. The corrugated spring 11 is formed to provide separate swelling portions 12 to abut against the bottom portions of the oil seal rings so that the oil seal rings 9 and 10 are allowed to move independently of each other. However, the corrugated spring having the shown structure contains the drawback that if one of the swelling portions 12 falls down in operation due to a high temperature condition, said falling down of the swelling portion affects the swelling portion forming a pair therewith, which eventually causes the falling down of the second swelling portion. Furthermore, the falling down or failure of a pair of theswelling portions 12 affects adjecent pairs of the swelling portions 12, and in this manner the spring force which pushes against the oil seal rings is gradually lost, thus causing a deterioration in the oil and gas tightening performance of the oil seal means.

SUMMARY OF THE INVENTION Therefore, it is'the object of this invention to remove the abovementioned drawbacks in the conventional oil seal means of rotary engines and to provide an improved oil seal means wherein the spring means is resistive to falling down even under high temperature operating conditions. Even when a part of the spring means has fallen down, it does not affect the remaining portion thereof and thus does not deteriorate the overall performance of the spring means which would injure the oil and gas tightening effect of the oil seal means.

The abovementioned object is accomplished, according to this invention, by an oil seal means of a rotary engine comprising a plurality of oil seal rings disposed one over the other and mounted in a common annular oil seal groove formed at aside wall portion of a rotor and spring means adapted to resiliently urge each of said oi] seal rings each, independently and axially, outwardly of the rotor, characterized in that said spring means includes a substantially flat base portion adapted to seat upon the bottom wall of said annular oil seal groove and a plurality of spaced spring portions extending from opposite edges of said base portion an inclined with respect to said base portion, said spring portions each supporting only one of said plurality of oil seal rings.

In the structure of the oil seal means according to this invention, each of said spring portions operates independently as a spring toapply its own spring force to either one of said oil seal rings without being directly affected by deformations or the falling down of other spring portions. Therefore, the oil seal ring supported by a plurality of such spring portions acting separately thereupon can be stably supported for a long period of operation.

According to a particular feature of this invention,

spring portion, whereby a high economy of the material expense is attained.

According to still another feature of this invention, in the spring means obtained from a substantially flat sheet, said base portion may have a plan shape of a uniform strip formed with rectangular projections extending alternately at opposite sides thereof, said spring portion being an integral extension of said projection, the extended portion being turned in the opposite direction with respect to the corresponding projection, whereby a relatively long span of the spring of a cantilever type is available to improve the resiliency of the spring and thereby to attain a good followablity of the oil seal ring over the unavoidably convexed or concaved inside surface of the side housing.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing,

FIG. 1 is a side view of an example of the rotary engine, showing the same with one of the side housings being removed for the purpose of illustration;

FIG. 2 is a sectional view showing an example of the conventional oil seal means provided at the side wall portion of the rotor;

FIG. 3 is a perspective view of the spring used in the oil seal means shown in FIG. 2;

FIGS. 4 and 5 are perspective views of two embodiments of the spring means used in the oil seal means according to this invention; and

FIGS. 6 and 7 are cross-sectional views Corresponding to FIG. 2 showing embodiments of the oil seal means according to this invention constituted by employing the spring means as shown in FIGS. 4 and 5, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, this invention will be described in more detail of preferred embodiments with reference to the drawing, particularly FIGS. 4-7.

FIGS. 4 and 5 show in perspective view two embodiments of the spring means to be incorporated in the oil seal means according to this invention, and FIGS. 6 and 7 show in cross-section corresponding to FIG. 2 the oil seal means of a rotary engine constituted by employing the spring means shown in FIGS. 4 and 5, respectively.

The spring means 13 shown in FIG/4 includes two portions separated by cuts 14 spaced lengthwise therealong (circumferential direction of the rotor) and extending over substantially the entire width thereof (radial direction of the rotor), one being a flat, belt-like base portion 15 and the other being spaced spring portions 16 each extending from said base portion and inclined with respect to said base portion. In this case, the spring portions 16 are extended from the belt-like base portion 15 in the opposing directions as inclined, each being deformed at the tip end portion thereof to present an abutting face portion 17 inclined by an angle to conveniently abut against the bottom portion of the oil seal ring. It is apparent that the spring means 13 can easily be produced by a punching out process ofa sheet material.

Thespring means 18 has the substantially same structure as the spring means 13 shown in FIG. 4, and therefore, the portions corresponding to those shown in FIG. 4 are designated by the same reference numerals in FIG. 5. It will be apparent that the spring means 18 shown in FIG. 5 can also be easily produced by a substantially same punching out process as the spring means 13 shown in FIG. 4.

In the conventional oil seal means as shown in FIGS. 2 and 3, the contacting surface between the spring 11 and the bottom wall of the oil seal groove 8 is small, whereby the heat transmitted from the high temperature combustion gases which leak in through the side seal 6 to the oil seal rings 9 and 10 is apt to be accumulate in the spring 11, thus heating the spring 11 up to a high temperature. Therefore, the spring 11 must be made of a high class spring material having superior resistance to high temperature, and still there is the danger that the spring may fall down due to high temperature. As compared with the conventional structure, in the oil seal means according to this invention as shown 1 contacts the bottom wall of the annular oil seal groove in FIGS. 47, the heat conducting distance of the spring portion 16 is relatively short and the base portion 15 8 over a sufficiently large area, whereby the heat transmitted to the oil seal rings 9 and 10 is advantageously passed to the body of the rotor 4, eliminating the danger of the heat accumulating in the spring means to heat the same up to a high temperature. Therefore, in the structure according to this invention, it is not necessary that the spring means 13 and 18 are made of a very highly classed material regarding the high temperature characteristic thereof.

I claim:

1. An oil seal means of a rotary engine comprising a plurality of oil seal rings disposed one over the other and mounted in a common annular oil seal groove formed at a side wall portion of a rotor, said annular oil seal groove containing a bottom wall and spring means adapted to resiliently urge each of said oil seal rings independently and axially outwardly of the rotor, characterized in that said spring means includes a substantially flat base portion to seat upon the bottom wall of said annular oil seal groove and a plurality of spaced spring portions extending from opposite edges'of said base portion and inclined with respect to said base portion, said spring portions each supporting only oneof saidplurality of oil seal rings.

2. An oil seal means according to claim 1, wherein said spring means is of a structure obtained from a substantially flat sheet.

3. An oil seal means according to claim 2, wherein said base portion has a plan shape of a zig-zag type extending lengthwise therealong, each cut-out portion of said zig-zag configuration being formed by displacing the corresponding portion from the remaining portion, said displaced portion being formed as said spring portion.

4. The oil seal means of claim 3, wherein said spring portion is deformed at its tip end portion to provide an abutting face portion adapted to abut against the bottorn portion of the oil seal ring.

5. An oil seal means according to claim 2, wherein said base portion has a plan shape of a uniform strip formed with rectangular projections alternately extending at opposite sides thereof, said spring portion being an integral extension of said projection, the extended portion being turned in the opposite direction with respect to the corresponding projection.

6. The oil seal means of claim 5, wherein said spring portion is deformed at its tip end portion to provide an abutting face portion adapted to abut against the bottom portion of the oil seal ring. 

1. An oil seal means of a rotary engine comprising a plurality of oil seal rings disposed one over the other and mounted in a common annular oil seal groove formed at a side wall portion of a rotor, said annular oil seal groove containing a bottom wall and spring means adapted to resiliently urge each of said oil seal rings independently and axially outwardly of the rotor, characterized in that said spring means includes a substantially flat base portion to seat upon the bottom wall of said annular oil seal groove and a plurality of spaced spring portions extending from opposite edges of said base portion and inclined with respect to said base portion, said spring portions each supporting only one of said plurality of oil seal rings.
 2. An oil seal means according to claim 1, wherein saId spring means is of a structure obtained from a substantially flat sheet.
 3. An oil seal means according to claim 2, wherein said base portion has a plan shape of a zig-zag type extending lengthwise therealong, each cut-out portion of said zig-zag configuration being formed by displacing the corresponding portion from the remaining portion, said displaced portion being formed as said spring portion.
 4. The oil seal means of claim 3, wherein said spring portion is deformed at its tip end portion to provide an abutting face portion adapted to abut against the bottom portion of the oil seal ring.
 5. An oil seal means according to claim 2, wherein said base portion has a plan shape of a uniform strip formed with rectangular projections alternately extending at opposite sides thereof, said spring portion being an integral extension of said projection, the extended portion being turned in the opposite direction with respect to the corresponding projection.
 6. The oil seal means of claim 5, wherein said spring portion is deformed at its tip end portion to provide an abutting face portion adapted to abut against the bottom portion of the oil seal ring. 